Butter knife



FIG. 1 is a front and top perspective view of a butter knife, showing my new design;

FIG. 2 is a front elevation view thereof;

FIG. 3 is a rear elevation view thereof;

FIG. 4 is a left side elevation view thereof;

FIG. 5 is a right side elevation view thereof;

FIG. 6 is a top plan view thereof;

FIG. 7 is a bottom plan view thereof; and,

FIG. 8 is an enlarged view of a portion labeled, ‘FIG. 8’ in FIG. 1.

The dash dot dash lines in FIGS. 1 and 8 are for the purpose of depicting the boundary lines of the enlarged view and form no part of the claimed design. 

CLAIM The ornamental design for a butter knife, as shown and described. 